Submarine signaling apparatus



Dec. 17, 193.5. 'w. 1.. GnwoFm' 2,024,214

SUBMARJVZNE SIGNALING APPAR A'rusM Filed Oct. 28, 1952 INVENTORWALLACE 1. awn-aka ATTORNEY I Patented Dec. 17, 1935 UNITED STATES v I BSIGNMG APPARATUS Wallace L. cums. BMW, w Submarine Signal Company,Boston, Mala, a I corporation of Maine Application October as, m2,Serial No. meat a Claim. (Cl. 181-45) The present invention relates tosubmarine sound diaphragms for use in receiving or sending sound wavesfor signaling purposes and for sound producers for depth soundingapparatus by the acoustic method, and perhaps more particularly to amethod of producing a composite plate in which one surface of the plateis a stainless or ncn-corrodible surface.

In the present art the method generally employed is tomake the wholeplate from non-corrodible steel if such a surface is desired. It hasbeen found practically impossible by the applicant to braze together ancn-corrodible steel plate with a plate of other material. One of. thereasons for this is that after the steel surface has been finished, theheating necessary in the brazing or other processes bring about a changein composition of the structure of the n'on-corrodible surface to suchan extent that it does not stand up. Even if the brazing is done beforethe surface is finished and the surface is afterwards finished, themetal does not appear to have the same wearing qualities that it didbefore. 7

Further than this it is practically impossible to obtain over a largesurface a perfect union so that in many cases the braz ingdoes not holdor is not able to stand up under the vibrational stresses and thepressures to which itis subjected. The applicant has discovered a methodby which a composite plate may be made in which a non-corrodiblesin-face can be provided and in which there is no uncertanty as to theunion of thetwodiiierentmetals f The present inventionwill be more fullydescribed ln connection with a submarine sound signaling diaphragm asillustrated in the draw- 7 ing in which Figure 1 shows the compositeplate applied by recesslng the surface of the dia phragm; Figure 2 showsthe submarine sound signaling device with a complete non-corrodiblesurface and Figure 3 shows a plan view of the plate shown in Figure l. v

In applying the sln'face to either type of diaphragm the method employedis substantially thesame. InFigure lthediap l'maybe first recessed asindicated in the por tlon 2. This diaphragm may be constructed of mostany type of metal, but it is usual to employ iron, steel or alloycomposition. The noncorrodible metal s, which is preferably a stainlesssteel comprising a steel. alloy.'=is deposited in the recessed portion 2by means of a welding torch which is provided with a gasto' prevent theoxidation of the melted metal. The non-corrodible' metalds preferablyused in the form of a drill rod andis meltedinglobuies orflowedaroundlntherecessedportionofthediaphragm' 2. Itis preferable in flowingthe metal in the recessed porti'cn or on the surface 'of the diaphragmto proeceedin some uniform pattern as, for instance, 5

around in a circle-or back andforth until the whole surface is filled.The surface may be covered once or more according to how-thick a coatingof non-corrodible material it is desired to have. It is possible also toregulate the thickness 10 of the coating by depositing more metal witheach coating, but in each case it is preferable tofill or coat theentire'surface uniformly.

IncoatingthedlaphragmshowninFlgurezawalll may be built up temporarilyabout the edge of the metal surface and within this wall the surface ofthe diaphragm may be built'up to the desired height. After the metal hasbeen deposited and cooled, the whole diaphragm is applied to, a grindingmachine and the surface is ground smooth and polished. I

In sound signaling apparatus it is frequently desired to tune dlaphragmsto certain sound fre-- quencies or pitches and in the present case thismaybe and is accomplished by taking material 25 from the inside 4 of thediaphragm rather than from the outer surface of the diaphragm. At thecenter of the plates are pole pieces I and I about which a coil may beplaced for energizing the diaphragms which: as shown in Figureopposedtooneanother.

If it is desired or before polishing,

the diaphragmmaybeheat treated tobring out the stainless steelproperties of the surface and polished afterwards. By the present methodof 35 construction it is possible to provide a plate in which thesurface is formed integrally with the whole mass and which is. free fromany heat stresses which may otherwise be present in-the brazing of twodifferent materials. Diaphragms of the present construction have beenparticularly useful in submarine sound pro- 'ducers for depth soundingin which the dinphragm must necessarily have a very large amplitude andhigh damping. In such structures 45 the diaphragm is worked more nearits physical limit and frequently in such casespitting of the diaphragmis apt to result. In the present type of dlaphragmconstructed accordingto the methods described above this difliculty. has been practicallyavoided. 3 v

Having now described my invention I claim:

1. A submarine. sound producer diaphragm comprising a metallic platehaving on thesur- 55 am y so faceadaptedtobeimmersedinthewaterathinplate of stainles steel. welded to the plate.

2. A submarine sound producer comprising a metallic base having theactive diaphragm surface removed and non-corrodible steel metal weldedthereinreplacing the same to form a continuous diaphragm surface.

3. A submarine sound producer diaphragm comprising a metallic base r inthe portion that wouldncrmally be the active part of the diaphragm andnon-corrodible steel metal flux welded in said recessedportion to form.a continuous surface with the part of the diaphragm external of theactive area.

'4. Adiaphrasmhavingabaseauda stainless steel coating therefor.

5.Adiaphragmhavinzabase comprisinga body portion and a peripheralportion by means ofwhichthediaphragmmaybesecuredtoa ship, the bodyportion having a stainless-steel coatinzandtheperipheral portionbeingun-TA. diaphragm comprising a body portionhavingarecessinoneface,andastainless-steel layerin the recess.

WALLACE L. GII'FORD.

